L10 FePt based exchange coupled composite bit patterned films

We demonstrate a 2.5-fold coercivity reduction in FePt based exchange coupled composite bit patterned media (ECC-BPM) by coupling a lower anisotropy Co/Pd-Co/Ni-multilayer system to the top of a high anisotropy FePt L1(0) film. Furthermore the tight switching field distribution (SFD) of the lower anisotropy system reduces the SFD of the ECC-BPM composite system compared to a single layer FePt film. The relative amount of switching field and SFD reduction in these ECC-BPM arrays agree with corresponding micromagnetic simulations. (C) 2011 American Institute of Physics. [doi:10.1063/1.3599573]